Constant current sources are known in the semiconductor manufacturing industry. One well-known type of constant current source is known as a peaking current source circuit. However, prior art constant current sources do not provide a constant current over a wide range of supply voltages.
In a prior art constant current source, the value of the output current with respect to the supply voltage has a maximum or “peak” at a particular value of supply voltage. The values of output current that correspond to values of supply voltage that are greater than the particular value of supply voltage are less than the maximum or “peak” value of output current. Similarly, the values of output current that correspond to values of supply voltage that are less than the particular value of supply voltage are less than the maximum or “peak” value of output current.
Because the specifications required for many electronic circuits require a range of supply voltages, prior art constant current sources are not adequate to bias many types of electronic circuits.
Therefore, there is a need in the art for a system and method that is capable of providing a current source that has an approximately constant value of output current over a range of supply voltages.